The field of medicine has long employed health care screening to diagnose and tract patients"" health. An annual physical examination is a well-known part of patient medical care.
A number of portable monitoring devices are used in medical monitoring. One well known device is the so-called Holter monitor which is an EKG monitor which typically uses a magnetic tape recorder to record EKG signals from a patient over extended periods of time. Another is a monitor for obtaining blood pressure readings over extended periods of time.
Hospitals, health clinics, and pharmacies, in addition to an active role is supplying medical supplies and pharmaceuticals, have actively promoted various health care screenings and wellness programs. Programs are sometimes offered with the help of other health care providers or coordinated on a national basis with groups such as the American Lung Association, the American Diabetes Association and the American Podiatric Medical Association.
Health care screening devices in hospitals, physician""s offices, businesses, and the like, in combination with the growing number of home diagnostic kits that are available have increased the efficiencies in health care delivery. Chain drug store operators have increasingly encouraged individual testing by making available in-store diagnostic testing devices. For example, a pharmacist who fills a high-blood pressure medicine for a customer may encourage the customer to regularly check blood pressure. The customer may use a blood pressure measurement and screening device in the drug store.
The offer of in-store testing commonly is highly popular among customers and greatly boosts the number of people visiting the store. In-store testing is valuable for positioning stores as health and wellness centers as well as retailers of health care products. In-store testing increases sales since a consumer who learns of a health problem through screening in the store has some likelihood of purchasing a home test kit to monitor the problem. For example, a customer who discovers a problem of high blood pressure through an in-store test is a likely candidate to purchase a home test kit.
In-store health care screening expands the pharmacist""s role in patient care through education. Test device manufacturers have advanced the design and functionality of products to simplify usage and improve accuracy. The challenge for further improvements in health care screening is to educate consumers about the need for medical tests, and demonstrate that many tests are effectively performed by publicly available devices or at home.
A present concern is that health screening is performed on an insufficient segment of the population to efficiently prevent or treat ailments. Other concerns are that health screening is too costly, limited in scope, and time-consuming both for individual patients and health care providers. Despite these deficiencies, a strong awareness exists of a need and desire for improved health screening procedures and equipment. Health care providers, insurance companies, and employers that ultimately pay for health care have encouraged development and usage of improved, accurate yet economic health screening facilities both for treatment and prevention of health care problems.
Generally individual doctors and small groups of doctors have insufficient capital to maintain a complete health screening facility. Even if more health care providers were suitably equipped, typically only a small part of the population exploits health screening facilities due to time and cost considerations and apathy.
What are needed are health screening devices, facilities, and methods that can be placed in locations that are convenient to health care customers. Suitable locations include retail outlets such as pharmacies or drug stores where customers already make health care purchases, but also include medical offices or hospitals, convalescence and elderly care homes, work places such as offices or factory sites, college dormitories, and the like. What are further needed are health screening devices, facilities, and methods that are convenient, efficient, low in cost, and professionally accurate in screening health care data.
A blood pressure measurement device and associated operating method utilize a measurement algorithm based on a plurality of measurements, supplying a unique ability to increase diagnostic and analytical success in detection. In an illustrative implementation, three measurement techniques are used in combination to improve overall measurement accuracy. A first of the three techniques is an ascultatory technique. A sound measurement acquired from a microphone located in the measurement cuff detects start and end Korotkoff sounds using a combination of filters. The auscultatory technique is a conventional method that is recommended by the American Heart Association and is similar to manual techniques used by a nurse or technician. The auscultatory technique and associated filtering techniques are well known by those having ordinary skill in the art. A second technique is an oscillometric technique that is commonly found in many low-cost blood pressure measurement devices. A pressure cuff is used to measure pressure oscillations, which are detected and monitored using mean pressure, and systolic and diastolic pressure ratios to identify systolic and diastolic blood pressure. A third technique, called a pattern recognition technique, measures a sound envelope and incorporates pattern recognition to identify systolic and diastolic pressures. A signal from the pressure sensor is used in addition to the three techniques to quantify the regions of sound under analysis.
The combination of measurement techniques produce multiple measurements that are combined using a voting technique to identify and discard improper results. Remaining measurements are averaged to within a predefined tolerance to improve the final results. Use of additional measurement techniques improve the measurement accuracy.
The ascultatory technique employs Korotkoff sounds to determine systolic and diastolic pressure points to determine measurement cycle timing. The oscillometric technique senses and monitors oscillations in a pressure waveform to locate systolic and diastolic pressures. A pattern analysis technique senses a pressure envelope and monitors the pressure envelope to locate characteristic changes in a sound envelope to determine systolic and diastolic pressures.
In some embodiments, the blood pressure measurement device includes a controller for controlling a pressure cuff to inflate the cuff in preparation for a blood pressure measurement and to slowly deflate, or bleed, the cuff to determine systolic and diastolic pressures and to generate a pressure waveform.
In accordance with one aspect of the present invention, a test apparatus includes an ascultatory analyzer, an oscillometric analyzer, and a pattern recognition analyzer. The ascultatory analyzer is capable of sensing and analyzing an audio signal using Korotkoff sounds to determine a systolic pressure and a diastolic pressure. The oscillometric analyzer is capable of sensing and analyzing oscillations of a pressure signal to determine the systolic pressure and the diastolic pressure. The pattern recognition analyzer is capable of sensing a pressure envelope and monitoring the envelope pattern to locate characteristic changes and thereby identify systolic and diastolic pressures. A comparing block compares the parameters measured using the distinct measurement techniques, determines mutually consistent limits for the distinct measurement techniques, and rejects measurement samples outside the determined limits. Results produced by the distinct measurement techniques are combined to quantify an optimal systolic pressure result and an optimal diastolic pressure result.
In accordance with another aspect of the blood pressure measurement device and operating method, a blood pressure measurement system includes a kiosk, a blood pressure interface coupled to the kiosk and capable of detecting a pressure signal, a microphone coupled to the blood pressure interface and capable of detecting an audio signal, and a blood pressure analyzer coupled to the kiosk, the blood pressure interface, and the microphone. The blood pressure analyzer includes a plurality of separate analyzers that detect blood pressure using a plurality of separate analysis techniques, the plurality of analysis techniques being based on analysis of audio signals, pressure oscillations, and pattern recognition of a pressure envelope.
In accordance with another aspect of the blood pressure measurement device, a method of measuring blood pressure of a test subject includes acquisition of at least three distinct measurement techniques that measure a plurality of physiological parameters. A first technique is an auscultatory technique including sensing an audio signal and analyzing the audio signal using an ascultatory analysis of Korotkoff sounds to determine a systolic pressure and a diastolic pressure. A second technique is an oscillometric technique including sensing pressure oscillations and analyzing the pressure oscillations using an oscillometric analysis to determine mean pressure, systolic and diastolic blood pressure, and to identify systolic and diastolic pressures. A third technique is a pattern analysis technique including sensing a pressure envelope and monitoring the envelope pattern to locate characteristic changes and thereby identify systolic and diastolic pressures. The method further includes comparing the parameters measured using the distinct measurement techniques, determining mutually consistent limits for the distinct measurement techniques, and rejecting measurement samples outside the determined limits. Results produced by the distinct measurement techniques are combined to quantify an optimal systolic pressure result and an optimal diastolic pressure result.